This application claims the priority of German Patent Application No. 199 63 031.3, filed in Germany, Dec. 24, 1999, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a combined disk and drum brake with an internally ventilated brake disk.
The German Patent Document DE 38 24 917 A1 discloses a brake drum with a brake ring, provided with a peripheral recess, into which a steel plate projects so that splashwater ingress into the drum is prevented and splashwater egress is improved. Furthermore, U.S. Pat. No. 4,313,528 discloses an internally ventilated disk brake with an Inside shoe brake, which exhibits on an inside friction ring an annular groove, whose base exhibits passage openings to the air guide channels between the friction rings of the brake disk, in order to protect against water entering into the inside shoe brake. To drain the water, a peripheral collar is laid down by a shielding plate and bent in the direction of the annular groove.
An object of the invention is, in the case of an internally ventilated brake disk with an inside shoe brake, to avoid splashwater, water or the like from penetrating onto the running surfaces of the inside shoe brake and to make it possible to specifically lead in and out the water both inside and outside the brake disk with simple means.
This object is achieved according to preferred embodiments of the invention by providing a combined disk and drum brake with an internally ventilated brake disk, comprising:
an inside and an outside friction ring,
a peripheral water guide plate at a shielding plate, and
an inside shoe brake arranged in a brake drum,
wherein the inside friction ring exhibits an annular channel which has a contracted groove opening opposite a base of the channel,
wherein air guide channels of the brake disk form water drainage channels, which are separated relative to a water draining interspace, defined by the shielding plate and a friction ring surface, and
wherein the water guide plate projects into the annular channel and is arranged in such a manner at an angle to the annular channel that in an approximately vertical water ingress position the guide plate is at an acute angle relative to the channel base and at the same time in an approximately vertical water egress position the guide plate forms a runoff slope.
In contrast to the separate water accommodation and common water drainage of waterxe2x80x94splashwater and the likexe2x80x94, penetrating into the brake disk, over air guide channels in an internally ventilated brake disk as the water drainage channels, the invention provides that the water drains toward the outside over two separate channels or through the air guide channels of the internally ventilated brake disk and over an interspace, formed by a shielding plate to the brake disk. Thus, the result in the case of the accumulation of large quantities of splashwater or liquids is better and faster drainage of water to the outside over the two separate channels or the interspace without loading the inside shoe brake with splashwater.
The air guide channels run between the two friction rings of the internally ventilated brake disk approximately parallel to the friction ring walls, where an upper orifice opening of the air guide channels or the water drainage channels lies in the faces of the friction rings, and the bottom orifice opening of the air guide channels is arranged at a 90xc2x0 angle relative to the drum wall in the region or in the direction of the brake drum and extends from here in the shape of an arc to the other straight air guide channel between the friction rings.
Due to these orifice openings, which belong to the air guide channels and are arranged separately from the orifice slit of the shielding plate, splashwater or liquid can drain immediately by circumventing the annular channel.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.